Question

Solve for x.
3x2 -4 = 8
0
+4
0
0
0

Answer 1

x = 4 or -4

Explanation:

3x² - 4 = 8

Add 4 to both sides.

3x² - 4 + 4 = 8 + 4

3x² = 12

Divide 3 to both sides.

3x²/3 = 12/3

x² = 4

Take square root of both sides.

±√x² = ±√4

x = 4 or -4

Answer 2

x = ±2

Explanation:

3x^2 -4 = 8

Add 4 to each side

3x^2 -4+4 = 8+4

3x^2 = 12

Divide each side by 3

3x^2 /3 = 12/3

x^2 = 4

Take the square root of each side

sqrt(x^2) = ±sqrt(4)

x = ±2